1. the Clearlooks theme which prevails in most things GTK on Debian (e.g.
Gnome, LXDE, not
sure about Xfce though)
2. the KDE theme is rather dominated by blue due to the Oxygen icon theme,
as well as the

Blue is fine with me, but at least different kind of blue then the
"baby blue".

Yes I was a bit naive about that too. As I learned in the meantime, we
have to use this sort of blue as a main color in the background if we
want use Clearlooks without any changes. Even "Space fun" does this,
if you look closely. The blue that clearlooks uses for active title
bars and marked options is a greenish/greyish sort of blue, that looks
like a rainy day or, to put it in a nicer analogy, like misty mountains.

But we are not alone. Fedora artists have the same problem. Take a
look at their (nevertheless sometimes beautiful wallpapers).